Philips 32PFL4507/F7 Inverter makes whining noise when plugged in.

[teljkon]

So my philips 32 inch tv went bad just before black Friday. Even though I grabbed a new Samsung to replace it on black Friday. I kinda want to see if I can repair it. When Its plugged in it makes a really whinny hi pitch sound coming from the inverter. The front panel acts as if there is no power at all. When I unplug it after its been plugged in for a while it makes a loud zzzzippp sound. I assume this is power discharging from the primary capacitor. When i disconnect the IO board it also stops making the whining noise. I assume it is a Io board from this behavior. My logic is that the IO board is the bottle neck and once its disconnected a fail safe in the inverter sends the power back into the circuit.

I can try to resize some pictures if some one wants me to but i cant see any bad caps. However I will be the first person to tell you i am not a electrical engineer so maybe some one here will know better. So what do you guys think?

[dick_barton]

Re: Philips 32PFL4507/F7 Inverter makes whining noise when plugged in.

Post some photo's of the inverter board(s)

Have you seen this
https://www.badcaps.net/forum/showth...32PFL4507%2FF7

[teljkon]

Re: Philips 32PFL4507/F7 Inverter makes whining noise when plugged in.

Help me with one thing when he says main board in that thread is he talking about the IO board/green board on the right in his pictures. I can get a used main board fairly cheap on ebay it may not be worth me buying a multi meter today to get this fixed.

How ever i may teach my self off of the broken one. The only thing I don't know how to do in the future is get power to a main board I wonder if I can jump off my arduino some how? However I could just try to replace solder those caps. I would need to buy a soldering iron though. Hmm Instant joy or brand new toy?

[teljkon]

Re: Philips 32PFL4507/F7 Inverter makes whining noise when plugged in.

pictures as requested I am afraid that I took a rather poor one of the I/O board but if you want to look at that i can get that up too.

[dick_barton]

Re: Philips 32PFL4507/F7 Inverter makes whining noise when plugged in.

Have a look at this video and check out the parts on your board that they are replacing in the video.
Do you have a multimeter for checking voltages. What DC voltage do you have across the two legs of C605 (330uF/200V) and at the connector, picture attached.

https://www.youtube.com/watch?v=RG53JLiATq0

[teljkon]

Re: Philips 32PFL4507/F7 Inverter makes whining noise when plugged in.

Have a look at this video and check out the parts on your board that they are replacing in the video.
Do you have a multimeter for checking voltages. What DC voltage do you have across the two legs of C605 (330uF/200V) and at the connector, picture attached.

https://www.youtube.com/watch?v=RG53JLiATq0

I do not have a multi meter sounds like an excuse to buy one at el harbor cheapo and see if i like tinkering with this stuff. report back once acquired.

[aaronwt6]

Re: Philips 32PFL4507/F7 Inverter makes whining noise when plugged in.

Funai crap inside. Just as almost all Philips, Magnavox, and Emerson stuff is. The squealing noise is most likely due to a short on the main board that's overloading the power supply. This main board is used in dozens of models. Unplug the main from the power supply then apply power. If the whining goes away, it's going to be a bad main board.

The loud 'zzzzippp sound' you are describing is normal on these Funai power supplies. They all do that 10-20 seconds after being unplugged.

[culcuhain]

Re: Philips 32PFL4507/F7 Inverter makes whining noise when plugged in.

Try reflowing the solder on the big inverter.... I have an Insignia that would do the same thing. Once soldered back up to fix the cold joints buzz went away....ymmv

[teljkon]

Re: Philips 32PFL4507/F7 Inverter makes whining noise when plugged in.

Funai crap inside. Just as almost all Philips, Magnavox, and Emerson stuff is. The squealing noise is most likely due to a short on the main board that's overloading the power supply. This main board is used in dozens of models. Unplug the main from the power supply then apply power. If the whining goes away, it's going to be a bad main board.

The loud 'zzzzippp sound' you are describing is normal on these Funai power supplies. They all do that 10-20 seconds after being unplugged.

I agree that it is the main board and for the cost of a main board. I should just replace it How ever I am curious about how to trouble shoot some thing like this. Just got my multi meter Sunday so ill be playing with it some time soon.

[teljkon]

Re: Philips 32PFL4507/F7 Inverter makes whining noise when plugged in.

Have a look at this video and check out the parts on your board that they are replacing in the video.
Do you have a multimeter for checking voltages. What DC voltage do you have across the two legs of C605 (330uF/200V) and at the connector, picture attached.

https://www.youtube.com/watch?v=RG53JLiATq0

So I think If I am reading this correctly your asking me to test the 5th pin on the ribbon connection to the main board? An I should be getting a reading of 3.3 or would that be 6.6? I have to be honest I'm not entirely certain what I am looking at with this diagram.

[teljkon]

Re: Philips 32PFL4507/F7 Inverter makes whining noise when plugged in.

I'm assuming this because i cant find a C605 on the inverter board but I also haven't cracked the TV open again to take a really close look.